sc16is7xx: Use struct_size() in devm_kzalloc()

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
    int stuff;
    void *entry[];
};

instance = devm_kzalloc(dev, sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = devm_kzalloc(dev, struct_size(instance, entry, count), GFP_KERNEL);

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 268098681856b4c06b82cb1189928915eb10259a..635178cf3eed538aa35bf49225a4886097e2e7b0 100644 (file)
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -1187,9 +1187,7 @@ static int sc16is7xx_probe(struct device *dev,
                return PTR_ERR(regmap);
 
        /* Alloc port structure */
-       s = devm_kzalloc(dev, sizeof(*s) +
-                        sizeof(struct sc16is7xx_one) * devtype->nr_uart,
-                        GFP_KERNEL);
+       s = devm_kzalloc(dev, struct_size(s, p, devtype->nr_uart), GFP_KERNEL);
        if (!s) {
                dev_err(dev, "Error allocating port structure\n");
                return -ENOMEM;